Construction machines such as, for example, excavators, loaders, dozers, motor graders, haul trucks, and other types of heavy equipment are used to perform a variety of tasks. During the performance of these tasks, the machines can operate in situations that are hazardous to an operator, under extreme environmental conditions uncomfortable for the operator, or at work locations remote from civilization. In addition, some of the tasks require very precise and accurate control over operation of the machine that can be difficult for a human operator to provide. Some of the tasks are also very repetitive and fatiguing for an operator. Because of these factors, the completion of some tasks by an operator-controlled machine can be expensive, labor intensive, time consuming, and inefficient. Accordingly, autonomous machines are often utilized under harsh conditions or in critical and repetitive applications.
Autonomous machines are capable of operating with little or no human input by relying on information received from various machine systems. For example, based on brake system input, steering system input, engine system input, obstacle detection system input, tool system input, etc., an autonomous machine can be controlled to automatically complete a programmed task. By receiving feedback from each of the different machine systems during performance of the task, continuous adjustments to machine operation can be made that help to ensure precision and safety in completion of the task. In order to do so, however, the information provided by the different machine systems should be accurate and reliable, and the control system should be capable of dealing with abnormal or fault conditions of system components.
U.S. Pat. No. 5,469,356 issued to Hawkins et al. on Nov. 21, 1995 (the '356 patent) describes a machine control system that provides for autonomous maneuvering during detected fault conditions. Specifically, the '356 patent describes a vehicle information management system (VIMS) that provides for status monitoring of various vehicle systems. VIMS collects information from dedicated sensors onboard a vehicle and from an engine manager. In the event that VIMS detects a fault condition associated with one or more vehicle systems, VIMS determines a warning level indicative of the highest fault level present on the vehicle. The warning levels include a Level I warning indicative of a sensor reading being out of a normal operating range, a Level II warning indicative of a condition that could cause vehicle damage if not corrected, and a Level III warning indicative of immediate danger to the vehicle. VIMS provides this information to a machine navigation module that controls the vehicle to continue operations, slow operations, or stop operations based on the warning level.
Although the autonomous control system of the '356 patent may be operable during a fault condition, the centralized system may be cumbersome and limited. That is, because VIMS is responsible for directly collecting all information and determining all recommended actions based on the fault conditions of each machine system, the number of system inputs may be limited by a computing capacity of VIMS. In addition, as the number of machines system inputs increases, a control complexity of the system also increases, thereby making VIMS cumbersome.
The disclosed autonomous control system is directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.